RD 50 CCE measurements and annealing studies on

RD 50 CCE measurements and annealing studies on proton irradiated p-type MCz diodes Herbert Hoedlmosera, Michael Molla, Michael Koehlerb, Henri Nordlundc a: CERN, b: University Siegen, c: Helsinki Institute of Physics RD 50 Workshop CERN, 16. 10. 2006 Contents • CCE setup • CCE Measurements on irradiated p-type MCz • CV/IV characterization of irradiated p-type MCz • Differences in reverse-annealing due to thermal donors RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser 1

RD 50 Investigated material 300 μm MCz by Okmetic Processing: ITC-IRST square MG diodes n+/p (batch SMART 2) W 066 – series: p-spray dose = 3 x 1012 cm-2 8 diodes with VDEP = 8 to 17 V W 182 – series: p-spray dose = 5 x 1012 cm-2 8 diodes with VDEP = 97 to 110 V After being processed together the two wavers were inhomogeneous: Differences in VDEP between the wavers and between different locations on the waver due to inhomogeneous TD generation according to talk by D. Menichelli, at the Hamburg-Workshop; Irradiation: 24 Ge. V/c protons @ CERN/PS up to Φ = 1016 cm-2 Die dimension: (5920 μm)2 Diode area (p+ implant): 13. 688 mm 2 Metal hole area: 4. 524 mm 2 (Φ 2. 4 mm) 1 Large guard (~90 μm) + 10 float rings 2 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 CCE system NIKHEF CCE system © Fred Hartjes signal shaping time: 2. 5 µs gain calibration factor: 245 e-/m. V temperature: down to -30 o. C with fridge + peltier bias: up to 1000 V guard ring: connected to ground noise: 567 e- + 4. 26 e- /p. F trigger rate with 90 Sr source: ≈ 50 -60 Hz control software: labview RD 50 Workshop 06: CERN 16. 10. 2006 3 Herbert Hoedlmoser

RD 50 CCE: measurement & analysis NIKHEF CCE analysis software automatic Landau fit and noise deconvolution pedestal events: < 2% separate pedestal measurement to deconvolute gaussian noise from signal 4 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Measurements & Parameters Measurements performed for the investigations • CCE: measured at -10 OC (-25 OC for highly irradiated diodes) • CV: measured at -10 OC and at room temperature (RT) • IV: measured at -10 OC and at room temperature (RT) • Annealing: at 80 OC RD 50 Workshop 06: CERN 16. 10. 2006 5 Herbert Hoedlmoser

RD 50 CCE for irradiated detectors irradiation: 24 Ge. V/c protons RD 50 Workshop 06: CERN 16. 10. 2006 annealing: 4 min @ 80 o. C 6 Herbert Hoedlmoser

RD 50 CCE as a function of fluence irradiation: 24 Ge. V/c protons annealing: 4 min @ 80 o. C 7 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 IRST-W 066 -22 Annealing: CCE irradiation: Φ= 3. 5× 1014 p/cm 2 CCE@10 o. C only depletion voltage changes, maximum CCE remains 8 Herbert Hoedlmoser RD 50 Workshop 06: CERN 16. 10. 2006 at 82%

Annealing: CCE RD 50 IRST-W 066 -20 irradiation: Φ= 3. 3× 1013 p/cm 2 IRST-W 066 -22 irradiation: Φ= 3. 5× 1014 p/cm 2 IRST-W 066 -21 IRST-W 066 -27 irradiation: Φ= 1. 1× 1014 p/cm 2 irradiation: Φ= 1. 1× 1015 p/cm 2 similar results for all fluences RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser 9

RD 50 Leakage current IV measurements @ room temperature Current related damage rate: α(1 Me. V n eq. ) = 4. 9 x 10 -17 [A cm-1] irradiation: 24 Ge. V/c protons RD 50 Workshop 06: CERN 16. 10. 2006 annealing: 4 min @ 80 o. C 10 Herbert Hoedlmoser

RD 50 Annealing: leakage current Annealing @ 80 OC; measurements at room temperature Measurement of the current related damage rate α as a function of annealing time: Comparison with parametrization of α: 11 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Annealing: leakage current Results for annealing of 3 different diodes: W 182 -21 Φ= 1. 1× 1014 p/cm 2 W 066 -20 Φ= 3. 3× 1013 p/cm 2 Currents corrected to reference temperature! 12 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 VDEP as a function of fluence CV measurements @ room temperature irradiation: 24 Ge. V/c protons RD 50 Workshop 06: CERN 16. 10. 2006 annealing: 4 min @ 13 80 o. C Herbert Hoedlmoser

RD 50 Annealing: VDEP IRST-W 066 -22 irradiation: Φ= 3. 5× 1014 p/cm 2 Evaluation of: ΔNeff ≈ 6 E 12 cm-3 ≡ Ny, ∞ reverse annealing amplitude 14 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

Annealing: VDEP RD 50 reverse annealing amplitude Ny, ∞ Evaluation of change in effective doping concentration as a function of fluence 15 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Difference in annealing behavior due to TDs? Difference between w 066 and w 182 series presumably due to TDs: Depletion voltage before irradiation ≈ 10 x higher for w 182! Higher TD concentration Reverse annealing of W 066 series (higher TD concentration) is delayed: 16 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Difference in annealing behavior due to TDs? Effect confirmed with independent evaluation of VDEP by CV and CCE VDEP by CV Reverse annealing of W 066 series is delayed 17 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Difference in annealing behavior due to TDs? Effect confirmed for different fluences: reverse annealing of W 066 series (higher TD conc. ) is delayed 18 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Difference in annealing behavior due to TDs? Comparison of reverse-annealing time constants 19 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Summary • CCE/CV/IV measured for p-type MCz diodes irradiated up to fluences of 1016 24 Ge. V/c p/cm-2 CCE(300 V): 93% @ 1. 2 E 14 p/cm 2 55% @ 1. 1 E 15 p/cm 2 (7. 4 E 13 1 Me. V/c n/cm 2) (6. 8 E 14 1 Me. V/c n/cm 2) • Annealing of an irradiated diode changes depletion voltage and leakage current but not CCE • TDs seem to influence reverse-annealing: higher TD concentration delayed reverseannealing? • Plan: systematic study of this effect by deliberate Herbert Hoedlmoser RD 50 Workshop 06: CERN 16. 10. 2006 TDs in p-type activation of MCz. 20

RD 50 backup slide Evaluation VDEP by CCE @ -10 OC VDEP by CV @ RT W 066 -21 / Φ=1. 15 E 14 p/cm 2 /8700 min@80 o. C evaluation by CCE usually leads to higher values of VDEP than CV: differences tue to T dependencies and slow CCE 21 measurement Herbert Hoedlmoser RD 50 Workshop 06: CERN 16. 10. 2006

RD 50 backup slide CCE: comparison to CV 1 = 23000 e- 1 = 1/(6. 7 p. F)2 W 182 -21 / Φ=1 E 14 p/cm 2 /4 min@80 o. C …. considering the T-dependencies in the measurements of irradiated detectors! RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser 22

RD 50 backup slide CCE(fluence) Material: standard p-type and oxygenated (DOFZ) p-type 23 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 backup slide Annealing: VDEP Reverse annealing for different fluences: 24 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 Annealing: leakage current Correction of the measured currents for T-dependency: 25 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

RD 50 backup slide CCE: measurement & analysis Example: p-type MCz IRST-W 066 -22 irradiation: Φ= 3. 5× 1014 p/cm 2 annealing: 512 min @ 80 o. C pedestal measurement RD 50 Workshop 06: CERN 16. 10. 2006 temperature: -10 o. C bias: 200 V deconvoluted landau Herbert Hoedlmoser distribution 26

RD 50 Setup: NIKHEF CCE system © Fred Hartjes 27 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser

“Environment” RD 50 NIKHEF CCE system © Fred Hartjes refrigerator RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser CV/IV box 28

RD 50 Setup: detector mounting …bonded to PCB support 29 RD 50 Workshop 06: CERN 16. 10. 2006 Herbert Hoedlmoser